This invention relates to mechanisms for towing vehicles and in particular to such a mechanism utilized in towing such vehicles by engaging and lifting a set of wheels of the vehicle.
Often conventional towing devices lift and pull a vehicle by hooking a chain or sling to its bumper, axle or undercarriage. Many such conventional devices have proven to be inadequate for towing newer vehicles having lightweight metal or plastic bodies which are easily damaged when pressure is exerted thereagainst by the towing device. Various attempts have been undertaken to provide alternative towing methods.
One alternative type of device raises the car by supporting the front or rear wheels thereof off the ground with a mechanism engaging mainly only such wheels. Several of these wheel-supporting devices are known in the towing art. Some of these devices are constructed of relatively thick steel, such that the devices are relatively heavy. Such heavy weight is of concern to a tow truck operator because, if the load on the rear of his truck is too much, the front wheels of the truck will leave the ground and the truck will be inoperable or at best have poor driving control. This loading problem is accentuated when the main pivot of the unit is placed at the rear end of the truck so as to be spaced rearwardly of the rear axle and when the winch and boom of the truck are not utilized as lifting aids.
Some of the conventional towing art devices are very complicated in structure and manufacture and tend to be either bulky or unstable in design. Additional hydraulic devices are often required for the operation of the lift mechanisms associated therewith. Another problem associated with some of the devices is that they interfere with or prohibit the alternative use of conventional towing devices thereby lessening the versatility of the tow truck. Other devices are somewhat unstable, in that they are free to swing from side-to-side and present a danger of loss of control of the towed vehicle.
Thus, there exists a need for a towing mechanism which does not support or directly engage the bumper or body panels of the vehicle to be towed but rather, supports members not easily subject to damage such as wheels or the like. Further, there is a need for such a mechanism which is relatively light in weight, yet strong enough to support a towed vehicle, which takes advantage of leverage and purchase principles to ease lifting, is not complicated in design or manufacture, provides stability in towing, can be utilized in conjunction with an existing conventional towing device, and efficiently and securely engages the wheels of particular vehicles with differing wheel spacing.